I think the concept behind this is a great take on a unique clicker game, it's just the upgrades that are lacking. Upgrading the pastry level and the max heat are no-brainers and work fine. I also found some utility in reducing the click temperature, because that allows you to stay in the green zone better. The auto-clicker has no utility as it is and the two other upgrades are okay, but don't really justify their price. It was fun to try and figure out a combination of upgrades that keeps the temperature steady, but I only did that for its own sake I think it was not required for beating the game as fast as possible.
The game looks great too, and the UI is well done as well, but I'm not sure the way you navigate it makes sense. I get that it's two buttons, but this was more annoying than it added to the game.